Re: [PATCH v3 1/1] mm: page_alloc: skip over regions of invalid pfns on UMA
From: Eugeniu Rosca
Date: Mon Jan 29 2018 - 12:07:03 EST
Hello Matthew, Pavel and MM people,
I am probably too impatient, but what would be the next step after
reaching [PATCH v3] and collecting two Reviewed-by signatures?
Is there a chance that this patch goes into v4.16-rc1 to be less of a
risk for the whole cycle?
Thanks,
Eugeniu.
On Wed, Jan 24, 2018 at 11:27:47AM -0500, Pavel Tatashin wrote:
> Looks good.
>
> Reviewed-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
>
> On Wed, Jan 24, 2018 at 9:35 AM, Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> wrote:
> > As a result of bisecting the v4.10..v4.11 commit range, it was
> > determined that commits [1] and [2] are both responsible of a ~140ms
> > early startup improvement on Rcar-H3-ES20 arm64 platform.
> >
> > Since Rcar Gen3 family is not NUMA, we don't define CONFIG_NUMA in the
> > rcar3 defconfig (which also reduces KNL binary image by ~64KB), but this
> > is how the boot time improvement is lost.
> >
> > This patch makes optimization [2] available on UMA systems which
> > provide support for CONFIG_HAVE_MEMBLOCK.
> >
> > Testing this change on Rcar H3-ES20-ULCB using v4.15-rc9 KNL and
> > vanilla arm64 defconfig + NUMA=n, a speed-up of ~139ms (from ~174ms [3]
> > to ~35ms [4]) is observed in the execution of memmap_init_zone().
> >
> > No boot time improvement is sensed on Apollo Lake SoC.
> >
> > [1] commit 0f84832fb8f9 ("arm64: defconfig: Enable NUMA and NUMA_BALANCING")
> > [2] commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible")
> >
> > [3] 174ms spent in memmap_init_zone() on H3ULCB w/o this patch (NUMA=n)
> > [ 2.643685] On node 0 totalpages: 1015808
> > [ 2.643688] DMA zone: 3584 pages used for memmap
> > [ 2.643691] DMA zone: 0 pages reserved
> > [ 2.643693] DMA zone: 229376 pages, LIFO batch:31
> > [ 2.643696] > memmap_init_zone
> > [ 2.663628] < memmap_init_zone (19.932 ms)
> > [ 2.663632] Normal zone: 12288 pages used for memmap
> > [ 2.663635] Normal zone: 786432 pages, LIFO batch:31
> > [ 2.663637] > memmap_init_zone
> > [ 2.818012] < memmap_init_zone (154.375 ms)
> > [ 2.818041] psci: probing for conduit method from DT.
> >
> > [4] 35ms spent in memmap_init_zone() on H3ULCB with this patch (NUMA=n)
> > [ 2.677202] On node 0 totalpages: 1015808
> > [ 2.677205] DMA zone: 3584 pages used for memmap
> > [ 2.677208] DMA zone: 0 pages reserved
> > [ 2.677211] DMA zone: 229376 pages, LIFO batch:31
> > [ 2.677213] > memmap_init_zone
> > [ 2.684378] < memmap_init_zone (7.165 ms)
> > [ 2.684382] Normal zone: 12288 pages used for memmap
> > [ 2.684385] Normal zone: 786432 pages, LIFO batch:31
> > [ 2.684387] > memmap_init_zone
> > [ 2.712556] < memmap_init_zone (28.169 ms)
> > [ 2.712584] psci: probing for conduit method from DT.
> >
> > Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx>
> > Reviewed-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> > ---
> > include/linux/memblock.h | 1 -
> > include/linux/mm.h | 6 ++++++
> > mm/memblock.c | 2 ++
> > mm/page_alloc.c | 2 --
> > 4 files changed, 8 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> > index 7ed0f7782d16..9efd592c5da4 100644
> > --- a/include/linux/memblock.h
> > +++ b/include/linux/memblock.h
> > @@ -187,7 +187,6 @@ int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn,
> > unsigned long *end_pfn);
> > void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn,
> > unsigned long *out_end_pfn, int *out_nid);
> > -unsigned long memblock_next_valid_pfn(unsigned long pfn, unsigned long max_pfn);
> >
> > /**
> > * for_each_mem_pfn_range - early memory pfn range iterator
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index ea818ff739cd..b82b30522585 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2064,8 +2064,14 @@ extern int __meminit __early_pfn_to_nid(unsigned long pfn,
> >
> > #ifdef CONFIG_HAVE_MEMBLOCK
> > void zero_resv_unavail(void);
> > +unsigned long memblock_next_valid_pfn(unsigned long pfn, unsigned long max_pfn);
> > #else
> > static inline void zero_resv_unavail(void) {}
> > +static inline unsigned long memblock_next_valid_pfn(unsigned long pfn,
> > + unsigned long max_pfn)
> > +{
> > + return pfn + 1;
> > +}
> > #endif
> >
> > extern void set_dma_reserve(unsigned long new_dma_reserve);
> > diff --git a/mm/memblock.c b/mm/memblock.c
> > index 46aacdfa4f4d..ad48cf200e3b 100644
> > --- a/mm/memblock.c
> > +++ b/mm/memblock.c
> > @@ -1100,6 +1100,7 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
> > if (out_nid)
> > *out_nid = r->nid;
> > }
> > +#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
> >
> > unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
> > unsigned long max_pfn)
> > @@ -1129,6 +1130,7 @@ unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
> > return min(PHYS_PFN(type->regions[right].base), max_pfn);
> > }
> >
> > +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> > /**
> > * memblock_set_node - set node ID on memblock regions
> > * @base: base of area to set node ID for
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 76c9688b6a0a..4a3d5936a9a0 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -5344,14 +5344,12 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
> > goto not_early;
> >
> > if (!early_pfn_valid(pfn)) {
> > -#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> > /*
> > * Skip to the pfn preceding the next valid one (or
> > * end_pfn), such that we hit a valid pfn (or end_pfn)
> > * on our next iteration of the loop.
> > */
> > pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1;
> > -#endif
> > continue;
> > }
> > if (!early_pfn_in_nid(pfn, nid))
> > --
> > 2.15.1
> >
> > --
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